Nowadays, common media playing devices such as televisions (TVs) and flat displays have become essential entertainment devices for the modern humans. Those media playing devices combining both functions of TVs and flat displays can not only provide a television channels for watching but also can be served as computer monitors. Within the tendency of developing various kinds of display components and image processing technologies, some of the media playing devices are capable of approaching the real image and sound without distortion. However, whether the audio volume intensity is at an appropriate level is significantly factored in a user's audio-visual feelings.
An external environment noise may affect that a user is forced to frequently adjust an audio volume of a media playing device. For instance, when the environment noise is made at a high level, the user has to manually increase the audio volume to hear clearer, whereas the user has to manually decrease the audio volume again as long as the environment noise is turned down. The intensity of audio volume output must be varied with satisfying the demand of the user's audio comfort. Under a manner that the environmental noise is varied frequently, the user has to manually adjust the audio volume over and over again. This would invoke inconvenient to watch television. For now, there are various multimedia systems introduced for automatically adjusting the audio volume based on the environmental noise variances. However, those conventional systems can not adjust the audio volume according to either the user's habit or different noise environment types, and thereby can not obtain an efficient audio volume adjustment and can not satisfy the needs on the user's audio comfort. Or else, those systems are too complicated to be convenient for the operation and to lower the manufacturing cost.